Revert "ConnectivtyService : Execute connectivityCheck in thread pool"

This reverts commit 2d276ef04ae00c9eaeb89a698df5b09d240fbd4b.

Change-Id: Id88ed6b6b0b97537de1f8b304af463c5c5d5a851
Merge "Revert "ConnectivtyService : Execute connectivityCheck in thread pool"" into du44